Lower unit for outboard motors



ug. M, 1936., J. G. RAYNIAK LOWER UNIT FOR OUTBOARD MOTORS Filed March 19,

Patented Aug. ll, 1936 n UNITED STATES 2,050,670 LOWER UNTT Foa oUrBoARD Mo'roas Joseph G. litayniak,A Waukegan, Ill., assgnor to Johnson Motor Company, Waukegan, Ill., a corporation of Delaware Application March 19, 1934, Serial No. 716,250

6 Claims.

This invention relates in general to a lower driving unit for outboard motors adapted to house the driving means for a propeller and tubular connections for directing cooling water to and from the motor.

An important object of the invention is in the provision of a lower driving unit of this kind in which the walls of the housing for enclosing the parts are made entirely of sheet metal.

A further object of the invention is in the provision of a sheet metal housing to which the supporting means within the housing may be attached.

A still further object of the invention is in the provision of a stream-lined sheet metal housing which is light and strong, easily constructed and assembled and relatively inexpensive as compared with cast metal housings.

A still further object of the invention is in the provision of an improved method of assembling and constructing sheet metal housings of this kind.

In Vthe drawing:

Fig. 1 is a sectional View of a lower unit constructed in accordance with the principles of this invention; Y

Fig. 2 is a section taken on the line 2--2 ofy Fig. l;

Fig. 3 is an elevation of the lower end of the. unit looking at the propeller shaft and gear open.- ing before they are inserted therein;

Fig. 4 is a section taken on the line 4-4 of Fig. 1; and

Fig. 5 is a section taken on the line 5--5r of Fig. 1.

It has been the practice for many years to make lower units for outboard motors of cast metal either forming a lower unit of the outline as shown in Fig. l in its entirety, or making it in sections which are rigidly secured together. This practice requires that the openings and bearings for the shafts, as well as the openings for2water passages in the casing, be produced by cores which are removed after the unit is cast and the openings and parts then suitably machined to receive the bearings and shafts which are mounted within the lower unit forv driving a propeller. This requires a more or less heavy casting, it necessitates a foundry as well as a machine shop, and the production operations take considerable time and consequently involve considerable expense.

The present invention proposes to eliminate' these di'iculties by providing a sheet metal casing made preferably in two main parts of thegeneral outline of the lower unit, which are secured together at the meeting edges by brazing, soldering or welding. Disposed between the opposite sides and attached to them as by spotwelding, is a built-upstructure which. .includes the shaft and bearing supporting parts, the water tubes, and the end plates. Thus the interior construction is assembled completely before the sides of the unit or casing are attached thereto and the edges of the sides welded or otherwise secured together.

Referring now more particularly to the drawing, a lower unit of suitable shape is shown Figs. l and 2 comprising opposite sides i@ and II with enlarged portions I2 adjacent the lower ends for providing suitable space for a driving gear I3 within the casing which is mounted noon a propeller shaft I4. Below the enlargements i2 the sides of the casing extend closely together to form a skeg I5 for protecting a propeller mounted upon the propeller shaft Ill. Intermediate the top and bottom of the casing is an anti-cavitation plate I6 which extends outwardly from` the casing at both sides thereof and overlying the upper ends of the blades of a propeller rotatable below it.

This construction is particularly adaptable for stream-lining and it will be noted particularly in Fig. 2 that the cross section of the casing above and below the plate I is only slightly larger than the diameter of a drive shaft t? which extends through it, the enlargement i2 being gradually increased from the front edge 23 of the casing. Thus the casing will pass through the water with minimumresistance so that it is adapted for high speed propulsion.

At the top of the casing there is an enlargement I9 which rounds outwardly at theA center to receive a bearing shell 20 and anend plate 2iY by which the unit is connected toa drive shaft casing 22. Y

Within the lower unit is a support for the drivel shaft I1 and for the propeller shaft vI 4 which com-- prises a sleeve 23 connected at its upper end to the lowerend'of shell 2i!v by means of a suitable spacer 24 which is threaded in the lower end of the shell and to the upper end of the` sleeve 23. The shaft I1 preferably extends loosely through the sleeve 23 and a iianged bearing 25 is located at the upper end of the sleeve 213, and a lower flanged bearing 26 is seated at the lower end of the sleeve 23 and held in place by a bevel gear 2l connected by a pin to the end of the shaft and engaging the flange of the bearing 26. p

Extending transversely of the drive shaft Il in the lower portion of the housing unit is the propeller shaft I4 having its bevel gear I3 meshing with the gear 21, and the forward end of the shaft is seated in a bearing 9 having a supporting casing 30. Seated in the opening formed by the enlargements I2 is a plate 3l having a central opening 32 suiciently large for inserting the gear I3 therethrough. This plate is secured by spotwelding it around the outer edge to the opposite casings and the plate, the lower endY of the sleeve 23 and the casing 30 for the bearing are integrally attached together by braces 33, 34 and 35 which are welded, brazed or otherwise secured to the several parts. It will be noted that the face plate 3| has three screw s ockets 36 extending from the face thereof by means of which a cover plate may be secured over the opening 32 to make it watertight. At the upper end and extending rearwardly and downwardly from plate 2| are water inlet and outlet tubes 31 and 38 which are connected through the plate as shown in Fig. 5 for providing water connections with suitable pipes in the drive shaft casing (not shown). At the lower ends these pipes 31 and 38 are separated and extend through the plate IG to which they are secured by welding or brazing to make a watertight joint. This plate I6 is attached within and below a rearward extension 4U of the side plates l0 and Il and projects laterally beyond them overlying the uppermost path of travel of the propeller and extends forward beyond the central portion of the sides as shown more clearly in Fig. 4. The plate is also secured to the sides by brazing or welding and the parts thus secured together are mutually strengthened and braced to produce a substantially integral anti-cavitation plate and stream-line casing construction which is so advantageous for high speed propulsion.

Attached at the rear and below the plate l5 is a water gathering hood 4| opening forwardly to receive water thrust rearwardly from the upper tips of the propeller blades, the forward edge 42 of the hood being cut at a slight angle as shown in Fig. 4, in receiving the water from the propeller. This hood communicates with the inlet pipe 31 so that water received by the hood will be forced upwardly through the pipe 31 for cooling the motor in a well-known manner.

Also disposed below the plate I6 and in advance of the propeller blades at the upper end of their stroke is a casing 43' attached at its forward edges to the sides ||l and of the casing as shown more clearly in Fig. 4, and forming a stream-line extension of these surfaces. The opening 44 is in advance of the propeller and conforms somewhat to the curvature of the propeller blade so that the blade in rotating will exert a maximum suction tending to withdraw water from the outlet tube 38 which extends into the casing 43 and from the casing 43 itself.

In carrying out this invention the plates I6, 2| and 3| are all assembled completely with the pipes 31, 38, the shell 20, sleeve 23, bearing housing 3U and the connecting braces before the side plates ||l and are attached. It will be understood that the parts are integrally fastened together by soldering, welding or brazing the parts, depending upon the materials which are to be connected. 'I'he side plates |0 and are then applied to the interior structure and they are secured to the plates in a similar manner to make a watertight joint and by spot-welding at various points 45 in order to hold the parts more rmly together. It will also be understood that where the casing parts are joined at the front edge |8 and at rear edges 46 and 41 the side plates are welded or brazed together so that when completely formed the structure is solid and integral in form and appearance, any rough edges are easily smoothed by grinding and bufling, and a complete unit is thus provided which has the necessary strength without an objectionable weight. Since outboard motors to which this unit applies are portable, this is an important consideration and the structure is both light and strong.

I claim:

1. A sheet metal lower driving unit, having separate similar side plates, an end plate, and an anti-cavitation plate all weldingly secured together, metal tubes secured in and extending through the end and anti-cavitation plates, and hooded casings secured to the under side of the anti-cavitation plate with their inside portions communicating with the ends of the tubes therein.

2. A structure in accordance with claim l in which the hooded casings are spaced apart but open toward each other to receive the outer edge of a propeller blade therebetween for water circulating purposes with respect to the tubes.

3. A sheet metal lower driving casing having opposite similar side plates, an anti-cavitation plate partially embracing a portion of the side plates and extending beyond and below an adjacent portion of the plates, metal hoods secured to the under side of the anti-cavitation plate and forming oppositely opening water discharge and gathering mouths, and means forming 'passages through the casing and in communication with said mouths.

fl. In an outboard driving unit, the combinaticn with side plates having a rearward extension, the lower margins of the said extensions of the respective plates being spaced apart, of an anti-cavitation plate forwardly notched to prof vide margins engaging said side plates externally, said anti-cavitation plate being secured to the spaced margins of the rearward extensions of the respective side plates and extending across the space to provide a closure therebetween.

5. An outboard driving unit comprising in combination a tubular drive shaft casing providing a drive shaft bearing, a drive shaft, a propeller shaft extending transversely with respect to the drive shaft, a forward propeller shaft bearing, a pinion on the drive shaft, a gear on the propeller shaft, a ring sufficiently large to receive said propeller shaft and gear, said ring being disposed at one side of said casing, a bracket arm connecting said ring with said forward bearing, means connecting said ring with the drive shaft bearing, and another bracket arm connecting the drive shaft bearing with the forward bearing, and a closure removably connected to said ring and providing a rear propeller shaft r bearing and a thrust bearing for said gear.

6. An outboard driving unit comprising in combination a tubular drive shaft casing providing a drive shaft bearing, a drive shaft, a propeller shaft extending transversely with respect to the drive shaft, a forward propeller shaft bearing, a pinion on the drive shaft, a gear on the propeller shaft, a ring sufficiently large to receive said propeller shaft and gear, said ring being disposed at one side of said casing, a bracket arm connecting said ring with said forward bearing, means connecting said ring with the drive shaft bearing, and another bracket arm connecting the drive shaft bearing with the forward bearing, and a closure removably connected to said ring and providing a rear propeller shaft bearing and a thrust bearing for said gear, together with a sheet metal housing comprising side wall portions joined forwardly of said forward propeller shaft bearing and connected therewith, said plates being also joined at their rear margins except at said ring and being respectively connected with peripheral semi-circular portions of said ring.

JOSEPH G. RAYNIAK. 

